Perform a character-by-character comparison of strings string1
and string2. Returns -1, 0, or 1, depending on whether
string1 is lexicographically less than, equal to, or greater
than string2. If -length is specified, then only the
first length characters are used in the comparison. If
-length is negative, it is ignored. If -nocase is
specified, then the strings are compared in a case-insensitive manner.

Perform a character-by-character comparison of strings string1
and string2. Returns 1 if string1 and string2 are
identical, or 0 when not. If -length is specified, then only
the first length characters are used in the comparison. If
-length is negative, it is ignored. If -nocase is
specified, then the strings are compared in a case-insensitive manner.

Search haystackString for a sequence of characters that exactly match
the characters in needleString. If found, return the index of the
first character in the first such match within haystackString. If not
found, return -1. If startIndex is specified (in any of the
forms accepted by the index method), then the search is
constrained to start with the character in haystackString specified by
the index. For example,

Returns 1 if string is a valid member of the specified character
class, otherwise returns 0. If -strict is specified, then an
empty string returns 0, otherwise an empty string will return 1 on
any class. If -failindex is specified, then if the function
returns 0, the index in the string where the class was no longer valid
will be stored in the variable named varname. The varname
will not be set if string is returns 1. The following character
classes are recognized (the class name can be abbreviated):

Search haystackString for a sequence of characters that exactly match
the characters in needleString. If found, return the index of the
first character in the last such match within haystackString. If there
is no match, then return -1. If lastIndex is specified (in any
of the forms accepted by the index method), then only the
characters in haystackString at or before the specified lastIndex
will be considered by the search. For example,

Returns a decimal string giving the number of characters in
string. Note that this is not necessarily the same as the
number of bytes used to store the string. If the object is a
ByteArray object (such as those returned from reading a binary encoded
channel), then this will return the actual byte length of the object.

Replaces substrings in string based on the key-value pairs in
mapping. mapping is a list of key value key value ...
as in the form returned by array get. Each instance of a
key in the string will be replaced with its corresponding value. If
-nocase is specified, then matching is done without regard to
case differences. Both key and value may be multiple
characters. Replacement is done in an ordered manner, so the key
appearing first in the list will be checked first, and so on.
string is only iterated over once, so earlier key replacements
will have no affect for later key matches. For example,

string map {abc 1 ab 2 a 3 1 0} 1abcaababcabababc

will return the string 01321221.

Note that if an earlier key is a prefix of a later one, it will
completely mask the later one. So if the previous example is
reordered like this,

See if pattern matches string; return 1 if it does, 0 if
it does not. If -nocase is specified, then the pattern attempts
to match against the string in a case insensitive manner. For the two
strings to match, their contents must be identical except that the
following special sequences may appear in pattern:

Matches any character in the set given by chars. If a sequence
of the form x-y appears in chars, then any
character between x and y, inclusive, will match. When
used with -nocase, the end points of the range are converted to
lower case first. Whereas {[A-z]} matches '_' when matching
case-sensitively ('_' falls between the 'Z' and 'a'), with
-nocase this is considered like {[A-Za-z]} (and probably what
was meant in the first place).

Returns a range of consecutive characters from string, starting
with the character whose index is first and ending with the
character whose index is last. An index of 0 refers to the first
character of the string. first and last may be specified
as for the index method. If first is less than zero then
it is treated as if it were zero, and if last is greater than or
equal to the length of the string then it is treated as if it were
end. If first is greater than last then an empty
string is returned.

Removes a range of consecutive characters from string, starting
with the character whose index is first and ending with the
character whose index is last. An index of 0 refers to the
first character of the string. First and last may be
specified as for the index method. If newstring is
specified, then it is placed in the removed character range. If
first is less than zero then it is treated as if it were zero,
and if last is greater than or equal to the length of the string
then it is treated as if it were end. If first is greater
than last or the length of the initial string, or last is
less than 0, then the initial string is returned untouched.

Returns a value equal to string except that all upper (or title)
case letters have been converted to lower case. If first is
specified, it refers to the first char index in the string to start
modifying. If last is specified, it refers to the char index in
the string to stop at (inclusive). first and last may be
specified as for the index method.

Returns a value equal to string except that the first character
in string is converted to its Unicode title case variant (or
upper case if there is no title case variant) and the rest of the
string is converted to lower case. If first is specified, it
refers to the first char index in the string to start modifying. If
last is specified, it refers to the char index in the string to
stop at (inclusive). first and last may be specified as
for the index method.

Returns a value equal to string except that all lower (or title)
case letters have been converted to upper case. If first is
specified, it refers to the first char index in the string to start
modifying. If last is specified, it refers to the char index in
the string to stop at (inclusive). first and last may be
specified as for the index method.

Returns a value equal to string except that any leading or
trailing characters present in the string given by chars are removed. If
chars is not specified then white space is removed (spaces,
tabs, newlines, and carriage returns).

Returns a value equal to string except that any leading
characters present in the string given by chars are removed. If
chars is not specified then white space is removed (spaces,
tabs, newlines, and carriage returns).

Returns a value equal to string except that any trailing
characters present in the string given by chars are removed. If
chars is not specified then white space is removed (spaces,
tabs, newlines, and carriage returns).

Returns a decimal string giving the number of bytes used to represent
string in memory. Because UTF-8 uses one to three bytes to
represent Unicode characters, the byte length will not be the same as
the character length in general. The cases where a script cares about
the byte length are rare. In almost all cases, you should use the
string length operation (including determining the length of a
Tcl ByteArray object). Refer to the Tcl_NumUtfChars manual
entry for more details on the UTF-8 representation.

Returns the index of the character just after the last one in the word
containing character charIndex of string. charIndex
may be specified as for the index method. A word is
considered to be any contiguous range of alphanumeric (Unicode letters
or decimal digits) or underscore (Unicode connector punctuation)
characters, or any single character other than these.

Returns the index of the first character in the word containing
character charIndex of string. charIndex may be
specified as for the index method. A word is considered to be any
contiguous range of alphanumeric (Unicode letters or decimal digits)
or underscore (Unicode connector punctuation) characters, or any
single character other than these.